Removing adhering matter from press platens, etc. - formed during prodn. of e.g. chipboard, by hot-pressing article contg. in outer layer mixt. of novolak, hardener, and aminoplast

摘要

Process for removing matter adhering to surfaces of heating plattens and auxiliary equipment of hot presses deposited during prodn. of wood materials comprises (1) applying or introducing in and/or an outer layer of an article prepd. for pressing a mixt. (I) of (A) novolac and hardener (B) aminoplast adhesive in ratio 1;0,1-1;2; and (2) applying, during pressing, (I) under action of heat and pressure to the surfaces bearing the deposits. (B) is urea-formaldehyde (UF) powder glue and/or melamine-formaldehyde powder glue, 2-20 Wt.% (I) is used on wt. wood particles in outerr layer. (I) also contains HCHO- reducing substance. (I) is added to wood particles during coating with the glue by mixing, and face of article for pressing not intended for effecting removal of deposits is provided with release agent. (I) is added to wood particles after coating with the glue. (I) is added to glue-coated wood particles before or during formation of article for pressing. (I) is added to chipboard or fibre matrix, press packet, or shaped article before conveying to press. USE/ADVANTAGE - Partic. during chipboard mfr. Deposits are removed without interrupting prodn. and without additional consumption of time and basic materials, process is more effective at removing stubborn deposits than similar process employing (A) and HCHO-donor as hardener (DD-219 219).